Bring back Hover

[psteinroe]

re-integrate the hover feature crate, expose it in the workspace api and integrate it into the language server.

We removed it when migrating to the new infrastructure.

we should also polish it to support more types and integrate it with our markup.

[Donnerstagnacht]

Is this about hover effects on symbols/db objects like showing a table definition?

[psteinroe]

Yes! It's certainly possible (answering to the other request)